I've tried a number of different saddles some with cut outs, some without. I'm now pretty happy with my usual seat, a Charge Spoon. Happy enough that I've got them on three different bikes. It's simple, cheap and as comfortable as anything I've tried. That's not to say it's perfect. On a long ride I still find myself a little sore from the constant pressure. I notice that I stand up on the pedals as much for relief of my backside as for a different pedalling motion.
If you're not so comfortable, I should point out that there are a lot of things to adjust before changing the saddle. Huge improvements can be made in most cases by tilting the saddle a little or adjusting the bike to balance weight between hands, hips and feet. I've done all the bike fit tweaks and still suspect there's room for improvement on my longer rides.
So I thought I'd try something different. Really different in fact. The Infinity L2 Bike Seat is a very unusual shape. At £295 it's also more than ten times the price of the Spoon. So I found a UK supplier willing to hire them out. Even that is £55 including postage. However, if I'd paid the full price I'd probably be convincing myself it was a great saddle so as not to feel I'd wasted my money!
I won't give a long description of L2, but direct you to the seat's science page. The idea is to remove the two main points of pressure, your sit bones. Instead they're cradled in the space within the outer frame. The official set up video, like all US instructional videos includes the phrase "go ahead and..." about six times per minute. It rushes through some vague measurements and suggests moving the seat post down when fitting the saddle. Oddly, I had to move mine up about 20mm as did other reviewers. I suspect the video is more about promoting the saddle than helping people to adjust it correctly.
I tried the saddle for a week, at first on my turbo trainer, only for about ten minutes. My legs ached. This is probably because I needed to move the seat post up.
That seemed to help and over the next two rides I moved it up a little more and felt more powerful again. I guess a proper bike fit would be needed to get this spot on.
The first good thing I noticed was that bumps and rough ground hurt less. Normally I'd wince or lift myself off the saddle. At first I thought my rear tyre had gone soft, but it was fine. The Infinity bike seat seems to provide more suspension, or maybe it's simply that I'd feel these bumps threatening to bruise my sit bones and the Infinity's large cut-out meant my sit bones weren't in contact with the saddle. I did feel a bit of extra pressure where the inside of my upper thighs rubbed the outer edge of the saddle. I can't say for sure if this would turn into a painful bruise on longer rides nor whether tweaking the angle would improve things.
I don't have any power measurements, but I'd say I rode about as fast as usual for similar effort.
For the two relatively short rides I used this saddle for, I'd say the Infinity L2 was the most comfortable saddle I've tried. Though for reference I'm not a professional reviewer and I've probably only tried about ten different saddles, six of them recently. Secondly, while the Infinity claims to be suitable for a wide range of body shapes, saddles tend to be a matter of personal preference, so your experience is likely to be different to mine. I thought the seat gave comfort where it was needed most, more like being in a hammock than on a seat.
On the downside, the price. Including postage it's over £300 from UK supplier Ten Point. You can buy a basic bike for that. There's nothing obvious in the construction of this seat that would justify that. There are no carbon nanotubes woven with unobtainium. It probably wasn't made in zero-gravity out of unicorn tears. The plastic and leather materials seem similar to those of saddles less than a quarter of the price, that are themselves considered to be premium saddles. What you're paying for, no doubt is the research that allowed this unique design, which was presumably extensive.
A more salient question for the consumer is simply whether the extra comfort is worth it. When riding LEL a cyclist might say they'd pay anything not to have saddle sores and perhaps this saddle would help. But there are many cheaper saddles to try, especially if you take the approach of buying an old one on eBay to see if it works for you and reselling it if it doesn't.
If the Infinity L2 cost £60 I'd already have bought one. As it is I'm still thinking about it.
At £295 it's more than ten times the price of the Spoon.